Soluble CD4 is considered to have a great potential in AIDS therapy including treatment and prevention of AIDS. In vitro studies have estimated that a large excess (1000:1) of soluble CD4 is needed to achieve a significant reduction in infectious particles. It is likely that an excess of soluble CD4 is needed constantly over prolonged periods during therapy in AIDS patients. Conventional methods of production (cell culture and bacteria) may not be suitable to produce soluble CD4 in large amounts in the least expensive way. We propose to produce soluble CD4 in transgenic chicken eggs using chicken ovalbumin promoter-enhancer signals fused to the coding sequences of soluble CD4 domain. Use of chicken eggs as bioreactors to produce soluble CD4 will be highly innovative and very inexpensive.